Added backend supported csv/json export functionality

spoolman/api/v1/export.py

@@ -0,0 +1,85 @@
+"""Functions for exporting data."""
+
+import io
+from collections.abc import Iterable
+from enum import Enum
+from typing import Annotated
+
+from fastapi import APIRouter, Depends, Response
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from spoolman.database import filament, spool, vendor
+from spoolman.database.database import get_db_session
+from spoolman.database.models import Base
+from spoolman.export import dump_as_csv, dump_as_json
+
+# ruff: noqa: D103,B008
+router = APIRouter(
+    prefix="/export",
+    tags=["export"],
+)
+
+
+class ExportFormat(Enum):
+    CSV = "csv"
+    JSON = "json"
+
+
+@router.get(
+    "/spools",
+    name="Export spools",
+    description="Export the list of spools in various formats. Filament and vendor data is included.",
+)
+async def export_spools(
+    *,
+    db: Annotated[AsyncSession, Depends(get_db_session)],
+    fmt: ExportFormat,
+) -> Response:
+
+    all_spools, _ = await spool.find(db=db)
+    return await _export(all_spools, fmt)
+
+
+@router.get(
+    "/filaments",
+    name="Export filaments",
+    description="Export the list of filaments in various formats. Vendor data is included.",
+)
+async def export_filaments(
+    *,
+    db: Annotated[AsyncSession, Depends(get_db_session)],
+    fmt: ExportFormat,
+) -> Response:
+    all_filaments, _ = await filament.find(db=db)
+    return await _export(all_filaments, fmt)
+
+
+@router.get(
+    "/vendors",
+    name="Export vendors",
+    description="Export the list of vendors in various formats.",
+)
+async def export_vendors(
+    *,
+    db: Annotated[AsyncSession, Depends(get_db_session)],
+    fmt: ExportFormat,
+) -> Response:
+    all_vendors, _ = await vendor.find(db=db)
+    return await _export(all_vendors, fmt)
+
+
+async def _export(objects: Iterable[Base], fmt: ExportFormat) -> Response:
+    """Export the objects in various formats."""
+    buffer = io.StringIO()
+    media_type = ""
+
+    if fmt == ExportFormat.CSV:
+        media_type = "text/csv"
+        await dump_as_csv(objects, buffer)
+    elif fmt == ExportFormat.JSON:
+        media_type = "application/json"
+        await dump_as_json(objects, buffer)
+    else:
+        raise ValueError(f"Unknown export format: {fmt}")
+
+    return Response(content=buffer.getvalue(), media_type=media_type)

spoolman/api/v1/router.py

@@ -15,7 +15,7 @@ from spoolman.database.database import backup_global_db
 from spoolman.exceptions import ItemNotFoundError
 from spoolman.ws import websocket_manager
 
-from . import externaldb, field, filament, models, other, setting, spool, vendor
+from . import export, externaldb, field, filament, models, other, setting, spool, vendor
 
 logger = logging.getLogger(__name__)
 
@@ -111,3 +111,4 @@ app.include_router(setting.router)
 app.include_router(field.router)
 app.include_router(other.router)
 app.include_router(externaldb.router)
+app.include_router(export.router)

spoolman/database/filament.py

@@ -144,7 +144,10 @@ async def find(
             elif order == SortOrder.DESC:
                 stmt = stmt.order_by(field.desc())
 
-    rows = await db.execute(stmt)
+    rows = await db.execute(
+        stmt,
+        execution_options={"populate_existing": True},
+    )
     result = list(rows.unique().scalars().all())
     if total_count is None:
         total_count = len(result)

spoolman/database/spool.py

@@ -198,7 +198,10 @@ async def find(  # noqa: C901, PLR0912
             elif order == SortOrder.DESC:
                 stmt = stmt.order_by(*(f.desc() for f in sorts))
 
-    rows = await db.execute(stmt)
+    rows = await db.execute(
+        stmt,
+        execution_options={"populate_existing": True},
+    )
     result = list(rows.unique().scalars().all())
     if total_count is None:
         total_count = len(result)

spoolman/database/vendor.py

@@ -83,7 +83,10 @@ async def find(
             elif order == SortOrder.DESC:
                 stmt = stmt.order_by(field.desc())
 
-    rows = await db.execute(stmt)
+    rows = await db.execute(
+        stmt,
+        execution_options={"populate_existing": True},
+    )
     result = list(rows.unique().scalars().all())
     if total_count is None:
         total_count = len(result)

spoolman/export.py

@@ -0,0 +1,66 @@
+"""Functionality for exporting data in various format."""
+
+import asyncio
+import csv
+import json
+from collections.abc import Iterable
+from typing import TYPE_CHECKING, Any
+
+from spoolman.database import models
+
+if TYPE_CHECKING:
+    from _typeshed import SupportsWrite
+
+banned_attrs = {"awaitable_attrs", "metadata", "registry", "spools", "filaments"}
+
+
+async def flatten_sqlalchemy_object(obj: models.Base, parent_key: str = "", sep: str = ".") -> dict[str, Any]:
+    """Recursively flattens a SQLAlchemy object into a dictionary with dot-separated keys."""
+    fields = {}
+    for attr in dir(obj):
+        # Check if the attribute is a column or a relationship
+        if not attr.startswith("_") and attr not in banned_attrs:
+            value = await getattr(obj.awaitable_attrs, attr)
+
+            if attr == "extra":
+                # Handle extra fields
+                for v in value:
+                    fields[f"{parent_key}extra.{v.key}"] = v.value
+                continue
+
+            # Handle nested SQLAlchemy objects
+            if isinstance(value, models.Base):
+                nested_fields = await flatten_sqlalchemy_object(value, f"{parent_key}{attr}{sep}", sep=sep)
+                fields.update(nested_fields)
+            else:
+                # Use only columns and simple data types
+                fields[f"{parent_key}{attr}"] = value
+    return fields
+
+
+async def dump_as_csv(sqlalchemy_objects: Iterable[models.Base], writer: "SupportsWrite[str]") -> None:
+    """Export a list of objects as CSV to a writer. Nested objects are flattened with dot-separated keys."""
+    # Flatten each object and get all column names
+    all_flattened = await asyncio.gather(*[flatten_sqlalchemy_object(obj) for obj in sqlalchemy_objects])
+
+    # Collect all unique headers across flattened objects
+    headers = set()
+    for flattened_obj in all_flattened:
+        headers.update(flattened_obj.keys())
+
+    headers = sorted(headers)  # Sort headers for consistent column ordering
+
+    # Write to CSV
+    csv_writer = csv.DictWriter(writer, fieldnames=headers)
+    csv_writer.writeheader()
+    for flattened_obj in all_flattened:
+        csv_writer.writerow(flattened_obj)
+
+
+async def dump_as_json(sqlalchemy_objects: Iterable[models.Base], writer: "SupportsWrite[str]") -> None:
+    """Export a list of objects as JSON to a writer. Nested objects are flattened with dot-separated keys."""
+    # Flatten each object and get all column names
+    all_flattened = await asyncio.gather(*[flatten_sqlalchemy_object(obj) for obj in sqlalchemy_objects])
+
+    # Write to JSON
+    json.dump(all_flattened, writer, default=str)